Modelling and Analysis of Tool Wear on a Cryogenically Treated CNMG120408SMRH13A Insert in the Turning of AISI4340 Steel Using Response Surface Methodology

The aim of this study is the modelling and analysis of tool wear on cryogenically treated CNMG120408SMRH13A inserts. Cryogenic treatment is carried out at -196°C for 48 hours, followed by tempering at 200°C for 2 hours. The AISI4340 steel is machined with cryogenically treated inserts by the turning process. Parameters, namely cutting speed, feed rate, and depth of cut, are selected as the input parameters at three levels. The flank and the crater wear are considered as output responses. The Scanning Electron Microscope (SEM) and X-Ray Diffraction analyses (XRD) confirm the formation of η-phase carbides on the treated surfaces. It is found that the results obtained from this model are sufficiently accurate for the prediction of tool wear. A good correlation is shown between the theoretical predictions and the experimental data. Direct and interaction effects of process parameters on the responses are studied by plotting graphs. As a result, it is found that cryogenically treated inserts have superior tool wear resistance, which has been confirmed by conducting confirmation tests

Line Balancing Analysis Of Tuner Product Manufacturing

The processing time and the number of operators have strong relationship with the productivity of production lines. In the tuner production line, three significant factors related to productivity through using of line balancing method are the number of operator, production tools/equipment, and production process. This study performed the line balancing method through simulation model in order to reduce the line unbalancing causes and relocate the workforce associated to idle time, eliminating the bottleneck, and at the same time maintaining/ improving the productivity. To analyze the production line, we use a develop simulation tool, called Fact-Model, to modeling the production line (with the graph of critical path network and working time) and the works estimated (related to the cycle time, takt time, non-value added activities, quantity, and cost). Fact-Model is facilitated with the features that enable the user to depict the real production flows by using their owned real pictures/photos taken into their simulation model

Effect of cryogenic grinding on fatigue life of additively manufactured maraging steel

Additive manufacturing (AM) is replacing conventional manufacturing techniques due to its ability to manufacture complex structures with near-net shape and reduced material wastage. However, the poor surface integrity of the AM parts deteriorates the service life of the components. The AM parts should be subjected to post-processing treatment for improving surface integrity and fatigue life. In this research, maraging steel is printed using direct metal laser sintering (DMLS) process and the influence of grinding on the fatigue life of this additively manufactured material was investigated. For this purpose, the grinding experiments were performed under two different grinding environments such as dry and cryogenic conditions using a cubic boron nitride (CBN) grinding wheel. The results revealed that surface roughness could be reduced by about 87% under cryogenic condition over dry grinding. The fatigue tests carried out on the additive manufactured materials exposed a substantial increase of about 170% in their fatigue life when subjected to cryogenic grinding

A Novel Approach for Groundwater Budgeting Using GIS in a Part of Pondicherry Region, India

The over extraction of groundwater from the coastal aquifers, result in reduction of groundwater resource and lowering of water level. In general, the depletion of groundwater level enhances the landward migration of saltwater wedge. Pondicherry is one such region with recent alluvium as the major formation. Since the study area forms a part of the coastal aquifer system this behaves as a fragile ecosystem. The present study has been attempted to calculate the extraction of water and to estimate the amount of recharge into this allu-vial aquifer by using groundwater level variations. The monthly water level fluctuation was observed during the study period (2000-2002) in eighteen locations. The maximum rise in groundwater level observed during 2000 was considered as the initial water level for the study and the subsequent decline in water level (draw down) was monitored monthly until the rising trend was noted. This indicates the fall in water level due to extraction.Later keeping the deepest draw down as the initial value increasing water level trend was studied until there was a notice of decline in groundwater level. This indicates as the rise in water level due to re-charge. This method of observation carried out at a single location was adopted for all eighteen locations. The spatial representation of these data for eighteen locations were carried out by using GIS and the area occupied by different groundwater level contours were calculated and the amount of water withdrawn/re- charged was estimated. The maximum recharge was noted in the central and the northern part of the study area when compared to the other regions. Similarly, the maximum discharge was noted in the northern and the southern part of the study area during the study period

4D printing of smart polymer nanocomposites: integrating graphene and acrylate based shape memory polymers

The ever-increasing demand for materials to have superior properties and satisfy functions in the field of soft robotics and beyond has resulted in the advent of the new field of four-dimensional (4D) printing. The ability of these materials to respond to various stimuli inspires novel applications and opens several research possibilities. In this work, we report on the 4D printing of one such Shape Memory Polymer (SMP) tBA-co-DEGDA (tert-Butyl Acrylate with diethylene glycol diacrylate). The novelty lies in establishing the relationship between the various characteristic properties (tensile stress, surface roughness, recovery time, strain fixity, and glass transition temperature) concerning the fact that the print parameters of the laser pulse frequency and print speed are governed in the micro-stereolithography (Micro SLA) method. It is found that the sample printed with a speed of 90 mm/s and 110 pulses/s possessed the best batch of properties, with shape fixity percentages of about 86.3% and recovery times as low as 6.95 s. The samples built using the optimal parameters are further subjected to the addition of graphene nanoparticles, which further enhances all the mechanical and surface properties. It has been observed that the addition of 0.3 wt.% of graphene nanoparticles provides the best results

Smart ceramic materials for homogeneous combustion in internal combustion engines: A review

The advantages of using ceramics in advanced heat engines include increased fuel efficiency due to higher engine operating temperatures, more compact designs with lower capacity cooling system. Future internal combustion engines will be characterized by near zero emission level along with low specific fuel consumption. Homogenous combustion which realized inside the engine cylinder has the potential of providing near zero emission level with better fuel economy. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In recent days, porous ceramic materials are being introduced inside the combustion chamber to achieve the homogeneous combustion. This paper investigates the desirable structures, types, and properties of such porous ceramic materials and their positive influence on the combustion process

Macromolecular crystallography research at Trombay

Neutron diffraction studies of hydrogen positions in small molecules of biological interest at Trombay have provided valuable information that has been used in protein and enzyme structure model-building and in developing hydrogen bond potential functions. The new R-5 reactor is expected to provide higher neutron fluxes and also make possible smallangle neutron scattering studies of large biomolecules and bio-aggregates. In the last few years infrastructure facilities have also been established for macromolecular x-ray crystallography research. Meanwhile, the refinement of carbonic hydrases' and lysozyme structures have been carried out and interesting results obtained on protein dynamics and structure-function relationships. Some interesting presynaptic toxin phospholipases have also been taken up for study